Large ears are a rare trait in a mainland mice population. a female mouse homozygous for very large ears arrives at an island that already contains mice after sneaking onto a boat. this will lead to a population with a higher incidence of big ears than the mainland population because of gene flow

Over the past 60 years, many amphibian species have experienced significant population declines and some species have become extinct. scientists suspected that local human activities such as the destruction of wetlands, regional pollution, and deforestation were the main reasons for these losses. however, research over the past 20 years reveals significant amphibian population declines in protected areas of the world, such as nature preserves and parks. these global declines suggest widespread problems including increased ultraviolet radiation, acid rain, and disease. in switzerland, for example, 14 of the 20 native amphibian species are threatened with extinction. chytridiomycosis is a fungal disease first identified in 1998 as a cause of massive amphibian deaths. in some severely impacted populations, a few individuals have survived, perhaps because of some natural resistance. if these resistant individuals continue to survive and prosper, new resistant populations might emerge. this would be an example of the founder effect artificial selection genetic drift natural selection sexual selection

What are tissues? a groups of tissues that work together b basic units of structure and function c groups of cells that perform the same function d multiple organs that perform a major function

What is the surface temperature of the ocean where hurricanes form? greater than 80 celsius approximately 27 celsius at least 76 celsius less than 10.5 celsius